1. Field of the Invention
The invention relates to a measuring system and a method for determining the quality of the feedback (feedback) of the received-signal quality transmitted by communications devices within communications systems, especially MIMO communications systems (Multiple-Input Multiple-Output communications systems).
2. Related Technology
In communications systems, such as UMTS or WiMax, the feedback transmitted by participating devices with reference to the channel quality is conventionally used for the adaptation of the transmission, for example, of the base station. For instance, in a closed-loop method, the pre-coding is modified in order to guarantee optimum reception at the terminal-device end. However, this method relies on as accurate an estimation of the transmission conditions or mobile-radio channel properties as possible at the receiver end. Although the participating devices are equipped with corresponding functions, no methods and devices for the verification of the correct function are so far known.
For example, European Patent Application EP 1 890 413 A2 discloses methods and devices for the transmission and reception of such feedback information from a communications device to a base station. However, a verification of this feedback information is not disclosed.